Air-brake safety-valve.



0. GIBSON. AIE BRAKE SAFETY VALVE. APPLICATION FILED APR.5, 1909.

937,991 Patented Oct. 26, 1909.

\ lUisrrED STATES PATENT oFFrcE. ,i

ORLANDO GIBSON, OF HOLLIDAYSBURG, PENNSYLVANIA, ASSIGNOR F ONE-FOURTH T0 C. H. GLAZIER, 0F HUNTINGDON,

PENNSYLVANIA, FIFTY-FIVE ONE-HUN- DBEDTHS TO C. E. FOSTER, OF PITTSBUBG, PENNSYLVANIA, AND TWENTY ONE- rBIUNIDBIEDTHS TO WILLIAM S. TAYLOR,

Specication of Letters Patent.

0F HUNTINGDON, PENNSYLVANIA.

Patented Oct. 26, 1909.

appnnation mea Apru 5, 1909. serial No. 487,886.

To all 'whom 'it 'ma/y concern:

Be it known that I, ORLANDO GIBSON, a citizen of the United States, residing at Hollidaysburg, in the county of Blair and State of Pennsylvania, have invented certain new and useful Improvements in Air-Brake Safety-Valves, of which the following is a specification. The present invention relates to improvements in safety devices for use in connection with fluid pressure brake systems.

vised for the As is well known in this art, when th pressure in an air brake system is relieved sufficiently, the brakes are applied. I f the pressure. issuddenly reduced by the breaking of a train pipe, bursting of hose couplings, or the parting of the cars in a train equi ped with air brakes, the brakes aretoo sud enly applied and set. This emergency application of the brakes .causes the movement of the vtrain to be checked to such a degree as to endanger Vthe lives ofthe passengers. If some of the cars on a train thus checked are not equipped with air brakes, the unchecked momentum of such cars permits them -to continue their movement and'they frequently collide-with the forward cars of .the train, doing great and avoidable damage. When equipped with my improved valve, such a sudden reduction of pressure in the air system is prevented; the forward section of a train having air brakes is still under control of the engineer if the train parts, and the brakes of the system are a plied gradually as the pressure is reduce throughout the train pipe.

' In carrying out my invention I interpose or insert in the train pipe ofthweairbrake system, one vor may be two .valves'to car, thevvalve or valves being located preferably in proximity to the angle cocks of the hose coupling at the end of the car.

In the accompanying drawings I have illustrated one example of the physical embodiment of. my invention constructed according to the best mode I have so far' depractical application of the principles.

Figure 1 is a vertical longitudinal section of the valve, fragments of the train pipe and mg. Fig. 2 is a transverse section on line As above stated, the safety device, which consists essentially of casing l and the inclosed parts, is interposed in the .train pipe, a portion of which 1s shown at 2,'and near the angle cock 3 of the hose cou ling at the end of the car. The casing 1 is ormed with short length tubes 4 and 5, whichare contrain pipe' and with the' angle cock.

l The casing 1 is normally open to the passage of air yunder pressure through a valve seat or ringA 6 which is located in the perforated horizontal partition 7 of the casing. This partition is integral with the vertical dividing wall8, and an enlargement 9 is present in the casing for the passage of compressed air around the wall 7.

Within the casin 1 and resting upon the top of the'wall 8 t ereof is an inner casing or cylinder 10, having a` bottom 11 with 4a central perforation 12. The upper open end of the cylinder 10 is closed 'by the cap 13 which is secured to the casing 1 by threads, as usual. The under facel of the cap piece 13 is bored out .or recessed forming a chamber 14:y .o f approximately the diameter of the c linder 10, anda central lug 15 projects rough the chamber '14. This lug 15 and the bess 16 of the cap are bored out to form a socket 17, and in this socket 17 the stem 1.9 and 20 are secured, is. adapted to 'rest when the air `pressure is normal, and is guided when lthe' piston head is moved under pressure. The plston 19, when the pressure 1s normal bears. against the lu 15 of the screw cap, as clear y shown in ig. 1, and a ring 21 is interposed between the underdaottom 11 of the cylinder 10, to aid in keeping thepassage open for air under pressure, .by holdmg the valve 20 against the underside of the cylinder 10. Air under pressure is admitted tov the chamber 14 through the duct or passage 22, and air may also be admitted to the interior of cylinder 10 through the perforation 23, the pressure thus being equal throughout the device when the vconditions are normal, that is, when the brakes are held off.

Now, 'assuming the brakes to be otf and 2-2 of Fig. 1.

pressure resent in the train pipe, with the parts as own in Fig.' 1, 1f the tram parts,

veniently threaded for connection with thev '18, uponwhich the pistonand valve heads slde of the piston and the upper side of the tem is sufficiently reduce or for some other reason, the pressure is suddenly reduced, say at Vthe right side of Fig. 1, the air rushes through valve seat 6 to the right, and is Withdrawn from cylinder 10 through port 23. Thepressure under piston 19 is thus relieved and the pressure above piston 19 in chamber 14, which has not been appreciably reduced as yet, forces the piston 19 and valve 20 downward until valve 20 closes the opening in the valve seat or gasket 6. With the valvecclosed down upon the seat 6, `and held there by pressure from the pipe 2 the escape of air in volume is cut oi'. As the piston and valve descend,l the piston 19 passes port 23, and gradual escape of air is permitted aroundy the closed valve by means of the duct 22, chamber 14 to the cylinder 10 and from thence through port y23 to the atmosphere. With this gradual reduction of pressure the brakes are applied gradually and the momentum of the train is thus gradually checked, and the forward part of the train may still be controlled by the engineer from his cab.

From the above description taken in connection with the drawings it is obvious that I-haveproduced a device which fulfills the conditions set forth as thgwpnrpose of my invention.

Havin thus fully described my invention, what Ic aim as new and desire to secure by Letters Patent, is v 1. Thecombination in an air brake system of a valve casin having a cylinder therein, a piston mova le in the cylinder, a spring on the shaft interposed between the piston and the bottom of the c linder, a stem and a valve on said stem, a valve seat ada ted to be closed by said valve, and means fbr closing said valve when pressure in the sys- 2.' The combination in an air brake system of a casing havin a cylinder therein, a piston and stem in t e c linder, a spring surrounding the stem an serving to normally force the piston away from the bottom of the cylinder, a valve on the stem outside the cylinder and a valve seat adapted to be closed by said valve, and a chamber formed above the piston containing air under pressure for closing said valve when pressure in the system is sufficiently reduced under the valve.

3. The combination with an air train pipe of a casing having a valve seat; a cylinder, a piston andv stein within the cylinder, a va ve outside the cylinder on the stem ada ted to close the seat, means for normally ho ing the valve above and out of engagement with the seat, a chamber above the piston containing air under pressure and a duct to connect said chamber with the train pipe, and a port from the cylinder to the train pipe whereby a gradual discharge of air is permitted when said valve is closed.

4. The combination with an air train pipe of a casing having a valve seat; a c linder, a piston and stem within thecylin er and a spring bearing against said iston, a valve on the stem outside the c lin er adapted to close said valve seat, an a chamber above the piston communicatingl with the Y' train pipe, yand a port from the cylinder to the air pipe whereby a gradual discharge of air is permitted when said valve is closed.

5. In combination with the train pipe, a casing secured therein, a valve seat in the casing, a cylinder secured inthe casing thereabove, a rod -passing through the cylinder and having sllding movement in a socket in the casing, a piston in the Icylinder mounted on the rod, a valve on the lower end of the rod outside the cylinder, means for normally holdin the valve in contact with the cylinder an a pressure chamber above the piston adapted to contain air under pressure for forcing the piston downward when the presi sure in a portion of the train `pipe is suddenlyreduced, said movement of the piston causing the .'valve to engage and close the opening in the valve seat. p

In testimo whereof I aix my signature, in presence o two witnesses.l

ORLANDO GIBSON.v

Witnesses ORLANDO BRENNEN, HOWARD PAPE. 

